cannot find module lazy preload Angular Routing

Question

I have looked at all the SO questions about this already, and still can't figure it out.

I'm preloading a module, and I'm getting the error:

ERROR Error: Uncaught (in promise): Error: Cannot find module './results/results.module' Error: Cannot find module './results/results.module' at :4200/main.js:48:11 [angular]

I've triple checked the spelling, and even made a small app to try and recreate it, but it works perfectly, I'm not sure what I'm doing wrong. Unfortunately I cannot post a live example for confidentiality.

AppRoutingModule

import { NgModule } from '@angular/core';
import { PlanComponent } from 'app/plan/plan.component';
import { MaintenanceComponent } from './maintenance/maintenance/maintenance.component';
import { Routes, RouterModule, PreloadAllModules } from '@angular/router';

const appRoutes: Routes = [
    { path: '', redirectTo: '/plan', pathMatch: 'full' },
    { path: 'plan', component: PlanComponent },
    { path: 'maintenance', component: MaintenanceComponent },

    // this is the failing module
    { path: 'results', loadChildren: './results/results.module#ResultsModule' },
];

@NgModule({
    imports: [
        RouterModule.forRoot(appRoutes, {
            preloadingStrategy: PreloadAllModules
        })
    ],
    exports: [RouterModule]
})
export class AppRoutingModule {}

AppModule

import { NgModule, Injector } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';
import { AppComponent } from './app.component';
import { AppRoutingModule } from 'app/app-routing.module';

... other components not including the lazy loaded module

...
imports: [
        BrowserModule,
        AppRoutingModule,
        FormsModule,
        HttpModule,
        BrowserAnimationsModule,
        SharedModule.forRoot(),
        MaintenanceModule
]
...

Preloaded Routing Module

import { NgModule } from '@angular/core';

... component imports

import { Routes, RouterModule } from '@angular/router';

const resultsRoutes: Routes = [
    {
        path: '', component: ResultsComponent, children: [
            { path: 'featurechild', component: featureChildComponent }
        ]
    },
];

@NgModule({
    imports: [
        RouterModule.forChild(resultsRoutes)
    ],
    exports: [RouterModule]
})
export class ResultsRoutingModule {}

Preloaded Module

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';

... other component imports

import { ResultsRoutingModule } from './results-routing.module';

...
imports: [
    CommonModule,
    ResultsRoutingModule,
    FormsModule,
    SharedModule,
...
export class ResultsModule {}

package.json

{
  "name": "gui",
  "version": "0.0.0",
  "license": "MIT",
  "scripts": {
    "ng": "ng",
    "start": "ng serve --deploy-url=/huskies",
    "build": "ng build --dev --deploy-url=/huskies",
    "prod": "ng build --prod --deploy-url=/huskies",
    "test": "ng test",
    "lint": "ng lint",
    "pree2e": "webdriver-manager update --standalone false --gecko false --ignore_ssl",
    "e2e": "ng e2e -uw fal"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "^7.0.2",
    "@angular/common": "^7.0.3",
    "@angular/compiler": "^7.0.3",
    "@angular/core": "^7.0.3",
    "@angular/forms": "^7.0.3",
    "@angular/http": "^7.0.3",
    "@angular/platform-browser": "^7.0.3",
    "@angular/platform-browser-dynamic": "^7.0.3",
    "@angular/platform-server": "^7.0.3",
    "@angular/router": "^7.0.3",
    "cesium": "^1.43.0",
    "core-js": "^2.5.7",
    "enhanced-resolve": "^3.4.1",
    "ng-event-source": "^1.0.14",
    "rxjs": "^6.3.3",
    "three": "^0.87.1",
    "zone.js": "^0.8.26"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "~0.10.5",
    "@angular/cli": "^7.0.4",
    "@angular/compiler-cli": "^7.0.2",
    "@angular/language-service": "^7.0.2",
    "@types/jasmine": "^2.8.9",
    "@types/jasminewd2": "~2.0.3",
    "@types/node": "^10.12.2",
    "codelyzer": "^4.5.0",
    "jasmine-core": "^3.3.0",
    "jasmine-spec-reporter": "^4.2.1",
    "karma": "^3.1.1",
    "karma-chrome-launcher": "^2.2.0",
    "karma-cli": "^1.0.1",
    "karma-coverage-istanbul-reporter": "^1.3.0",
    "karma-jasmine": "^1.1.2",
    "karma-jasmine-html-reporter": "^1.4.0",
    "protractor": "^5.4.1",
    "rxjs-tslint": "^0.1.5",
    "ts-node": "~3.3.0",
    "tslint": "^5.11.0",
    "typescript": "^3.1.6"
  }
}

folder structure (everything is in the root app directory):

results/results.module.ts
results/results-routing.module.ts
app.module.ts
app-routing.module.ts

Answer 1

Sometime ng doesn't detect some reason.

Can you run the command again

ng serve

If you are running through npm command then

npm start